Portal downloaded for free 1.5 million times

Since Portal went on Steam for free, it has been downloaded over 1.5 million times.

Valve didn’t provide a breakdown of how many downloads were of the PC version versus the Mac version. Portal is one of the newly released games with the ‘Steam Play’ feature- allowing you to play the game on Mac or PC using the same Steam account.

Portal became free last week, and that promotion will continue until May 24, after which it will again be sold as normal for RRP of £16.99.

In a statement likely to set forums and chatrooms ablaze, Valve also said that Portal is one fifth as likely to crash when running on a Mac than it is when running on Windows.

The second round of Steam Mac releases begins today as well.

The second round of Steam for the Mac launch titles are available now as well. This week’s collection features a dozen games headlined by the first cross-platform multiplayer games offered via Steam.

This first set of titles that allow for PC vs. Mac cross-platform gaming include the co-op zombie hit Killing Floor, Altitude, and Madballs in Babo: Invasion.

“We were thrilled when we learned that Steam was coming to the Mac platform and started working on a native Mac version of Killing Floor immediately,” said John Gibson, President of Tripwire Interactive, creators of Killing Floor. “Steam’s advanced multiplayer support on both the PC and Mac has enabled us to bring Killing Floor to a whole new audience on the Mac and introduce them to the existing PC player community.”

To celebrate the launch of these titles, Killing Floor will be offered at 33% off its regular price (for a limited time). An Altitude Free Weekend promotion is available now on Steam, and those who wish to purchase the game and play beyond the weekend may pick it up at 50% off its regular price. And Madballs in Babo: Invasion is also available at 50% off its regular price.

More single player games are also available today including Sam and Max: The Devils Playhouse Episode 2, Hearts of Iron 3, and more.

An additional collection of Mac titles will launch next week via Steam.